In the Wolof culture in Senegal, young girls' heads are shaved to signify that they are not yet mature. When they come of age, only then do they grow their hair out, Nelson said.

When Africans were captured and enslaved, all heads were shaved, not for disease control, as was the official reason stated, Nelson said, but to mentally prepare them for slavery.

"It was to make everyone the same," she said. "Royalty, warriors, married women and others all wore their hair differently, but with their heads shaved, that all disappeared."

Other kinds of differentiation and symbols of acceptance came to the fore during slavery in America, Nelson continued. House slaves were given more time to work with their hair so they could be more "presentable" and imitate hairstyles of their slave owners. But field slaves had no time to devote to their hair nor did they have appropriate combs for it, so all they could do was wrap it in rags.